Conventionally, there has been known an organic EL panel (see, e.g., Japanese Patent Application Publication No. 2003-257617) having as a light source a thin-type organic EL light emitting device with high brightness and a wide viewing angle. The organic EL panel is formed by laminating, on a transparent glass substrate, an anode electrode layer that is a transparent electrode made of ITO (Indium Tin Oxide) or the like, a light emitting layer made of an organic compound, and a cathode electrode layer that is a metal electrode. In the organic EL panel described in Japanese Patent Application Publication No. 2003-257617, a solution containing an organic EL material is sprayed on a rectangular substrate, and an organic EL substrate on which a group of organic EL devices is arranged in a matrix shape is manufactured. Further, each angled portion of the substrate is chamfered.
This organic EL panel generates excitons of organic compounds included in the light emitting layer by applying a DC voltage from a constant current source to electrode terminals electrically connected to the anode electrode layer and the cathode electrode layer, and extracts light emitted when the excitons return to a ground state to the outside.
Recently, there has been known a module which is formed by accommodating in a casing a combined structure of an organic EL panel and a circuit substrate having power supply elements such as a power distribution pattern and the like in order to easily handle an extremely thin organic EL panel or facilitate supply of power from the outside, or an illumination device having a plurality of such modules.
However, in the conventional organic EL panel, the electrode terminals for supplying power to the organic EL panel are provided near main sides of the substrate. Therefore, when an operator handles the organic EL panel, wirings are damaged by an operator's contact with the electrode terminals.
In the organic EL panel described in Japanese Patent Application Publication No. 2003-257617, cutoff portions are formed at the substrate in order to provide direction in handling the substrate. However, when an operator handles the substrate or the casing accommodating the substrate or arranges a plurality of organic EL panels in an illumination device, the circumference of the substrate where the electrode terminals are disposed may be held by the operator, which may cause damages to the wirings connected to the electrode terminals.
Moreover, an operator may directly hold the organic EL panel, so that the surface of the organic EL panel may be contaminated with fingerprints.